Gulf Coast Prairie LCC Takes a Close Look at Freshwater Mussels

Gulf Coast Prairie LCC Takes a Close Look at Freshwater Mussels

Native freshwater mussels play a critical role in river and stream ecology by influencing nutrient cycles and macro-invertebrate diversity. Mussels are also sensitive to changes in aquatic habitat conditions including water quality, fish communities, and physical changes in the streambeds, which make them a good indicator of aquatic habitat status. However, in spite of their broad distribution and species diversity, relatively little is known about the life history, distribution, and ecology of these important bivalves. What is known is that freshwater mussels have drastically declined in many areas due to habitat changes, water pollution and over-exploitation. For all these reasons, the Gulf Coast Prairie Landscape Conservation Cooperative (GCP LCC) Steering Committee designated the most diverse genus of mussels in the LCC's landscape, Quadrula spp., as a focal group in their Science Strategy. Before the LCC could design conservation measures for the genus, it needed to find out what was known about Quadrula mussels and what conservation approaches hold promise for these animals.

A recently-completed study funded by the GCP LCC and led by Dr. Dana Infante and Dr. Wes Daniel of Michigan State University is providing critical answers. The study began by documenting what is known about freshwater mussels in the rivers and streams of eastern Texas and Oklahoma and the lower Mississippi drainage in Louisiana through an extensive literature review. The researchers examined over 167 sources including peer-reviewed journals, State Wildlife Action Plans, and gray literature from state and federal agencies and located nearly 1,000 relevant documents. From that list they created an annotated bibliography of the 157 most important publications since 1980 related to the Gulf Coast Prairie region, focusing on information on mussel location and management actions by the foremost experts in both agencies and the academy.

Drs. Infante and Daniel hosted two expert webinars to engage regional scientists and managers in discussion of the greatest research needs and to identify major conservation challenges and potential conservation actions for Quadrula species. Others who could not participate in the live webinars were able to view recordings and submit information through a survey. The highest priority research needs were identification of life-history traits and host fish species, classifying ecological flows for freshwater mussels, species distribution surveys or models, and identification of sites that are important for conservation of Quadrula species. The primary current threats to these mussels include hydrologic alteration, channel alteration, anthropogenic land use, fragmentation from dams or road crossings, sedimentation and non-point source pollution. Additional future threats include land use changes, climate change, human population growth, and introduction of non-native mussel species.

Drs. Infante and Daniel also compiled a spatially-linked Gulf Coast Prairie Mussel Database drawing on their literature review and publicly available natural history databases. This database, along with a summary of expert opinion on conservation actions will provide decision support to help LCC partners identify and prioritize stream reaches and potential conservation actions targeting Quadrula spp.